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'78 K20 - RootBreaker from 1990 - nov 2025 8.1L not runnin

Wow engine looks like it sat on the bottom of the ocean. I'd take a good hard look at the rust on that regulator/fuel rail and replace it if it's questionable.
 
Wow engine looks like it sat on the bottom of the ocean. I'd take a good hard look at the rust on that regulator/fuel rail and replace it if it's questionable.

you have to remember were east coast.. this is normal.. lol..
while that looks bad, my last engine was way worse... if its surface.. and can run for now.. till i get it all worked out, then will be fine.

after getting it running and bugs worked out, i hope to replace (since alt and starter will be new) then do water pump and power steering pump... sanding and painting all brackets as i go...
then not much left.. replace fuel rail, add the perdy plastic top...

then tear it all down and go inside..
rings/bearings/big cam/new injectors
and paint..

then all good...
 
my current dealings that are in the 8.1L thread...

Swap info:

- The L18 8.1L has the same foot print as older BBC engines and will bolt in the same as any other older SBC and BBC. In fact, the L18 will accept any exhaust manifold or header from older BBC engines. The starter motor from any older SBC and BBC for use with a 168 tooth flywheel will also fit the L18. Any transmission from an old PowerGlide, TH350, TH400 to Allison, to NV4500, etc. will bolt on to it as well.


Today I am going to run out and get the flywheel bolts to put my 1991 sbc 350 flywheel/clutch and pressure plate on....

I tried putting my starter on, and the holes on my starter dont seem to take the bolt. ill have to post pics later but i found it odd that i couldnt get my starter on. i have to dig up my sbc 350 starter bolts out to take a look at the difference.


now my engine didnt come with an alternator. So, what would be a desired alternator to add?


Sadly, I've pro been chasing these issues due to this the entire time. It has been a long road but at least at this point I know everything except the block at brand new... Here's the part number and application I ordered. It covers a lot of models but should be correct for my application.

View attachment 347987

View attachment 347988

is this part needed for the swap into our trucks? wow did I miss this?
while my first engine i bought came with wiring harness and ecu, it did not come with this...

but this second engine.... HAS IT!!!!!!
so i best save it.. i was looking at it last night going.. i have no clue what this is.. and if i need it...


As I’ve been prepping @ZooMad75 8.1 the past few days I was able to grab a few clear photos of the method to remove the oil bypass valve for those that chose not to run engine oil coolers…or just simply don’t have the real state to mount a cooler anywhere. The update is at the bottom of Post 24 on Page 2 of this thread

so is there a reason to not run the cooler? that is my next thinking.. my current engine has the cooler lines and they were not cut. Now I dont know if they will be long enough to stretch to wherever I may need the cooler to be..
just thinking ahead if its worthy of doing it or removing it.. as im prepping my engine slowly...


these are all important to me.. hopefully all goes well and i can get some more completed over the next few days.

i started college again and im working and still doing mma so there is no real time, thus i try and do some here and there.
 
That's the tac module for the 2003 throttle body. I won't know if this works 100% with my 2001 ecu until I finish the rewire and reinstall the ecu. I hope it does but there's some talk that they're not compatible. I have used it briefly with some pedal range issues until my computer issues returned.

If you plan on using your fly by wire throttle body you will need that tac module and the factory pedal.
 
sometimes im not the sharpest knife in the drawer.. lol..
turns out the flywheel i ordered yesterday CAME IN ALREADY!!!!
and the not sharpest knife comment.. i didnt order the flywheel bolts.. doh
 
there, this is cleaner.. and fyi... I haven't done it yet so I cant vouch for the credibility of some things... thus the sensor replacement.. ill check it after truck is in but will replace while out. I also read that they starting making one with the connector on a 90 degree bend so will make sure that is what I get...



this is actually in the 8.1L resource thread but I want to pull it into here as I'm going to also update some pieces...

Ok adding my section to this. Was going to do my own but figured id stick it in here as it is not a high traction 5 million post thread. anyway.. I got through 3 pages to answer some of my questions. Got 13 more to go but gotta cook on the grill and family/eating time.be back later but thought I would share my notes I am taking.
correct me if I have some things wrong please..
this is jotted notes and all over the place. Tried keeping it somewhat organized and will clean it up later when things are confirmed...

8.1L parts...
* High Pressure fuel pump - EP381 Fuel pump
* fuel supply and return 2001 - 2003 The Workhorse part numbers for these lines are W0000539 Supply, W0000540 Return.
* regulator - built into 2001 - 2003 fuel rail
* Motor Mounts - Energy Suspension engine mounts - Energy Suspension 3.1116R
* Motor Cross Member - ORD GU32005
* Clutch stuff - 8.1L specific flywheel and pilot bearing (12582964 is the flywheel, 12563485 flywheel bolts & 12557583 pilot bearing). Supposeldy TBI 350 flywheel is internal balance thus should work and will find out
* EGR Block Plate
* Crank Sensor - can replace in truck against myth that you cant
* Accelerator pedal - can use gas pedal but 6.5 turbo diesel is a direct bolt in and 2 pins are different (pin A to J and J to A)
*mount pcm - 15764028 BRACKET - PCM W0007848 BRACKET - TCM 15003790 x2 BRACKET - TCM legs

Notes
* fuel lines - supply from motor 4-5 feet then put a filter in, click it in then take another hose and click it in and run to float assembly
* There is a small nub on the driver’s side of the engine that will need to be ground down just a tad so the engine mounts will bolt to the engine.
* Trans - SM465 - pull guide pins and will bolt to motor
* Clutch - use current sbc 350 pressure plate, clutch, etc? read need to drill holes for metric bolts for clutch?
* Exhaust - I don’t recommend using the 8.1L exhaust manifolds as they will hit the frame on an older truck. Any big block header or exhaust manifold (396, 402, 454, etc) will fit the 8.1L.
* Alternator - wire for charge goes where? gonna be bigger than my 60a I assume...
* Reading that low mount AC hits frame, but I do not need AC and have this style bracket - just remove and smaller belt.
Wiring
* Where to mount pcm - The Workhorse W0000393 ECM housing is the plastic piece the ECM snaps into.
I just used the TCM bracket as a cover per’se.
15764028 BRACKET - PCM
W0007848 BRACKET - TCM
15003790 x2 BRACKET - TCM legs
The 8.1L PCM is capable of managing dual fuel tanks. Get a tune from a cab and chassis 8.1L truck equipped with dual tanks, provide a fuel level signal from each tank and the PCM will operate your existing transfer pump to maintain the level between the two tanks. The PCM just controls a fuel pump relay for the transfer pump.
* My suggestion is to have them toggle off Torque Management, Toggle off EGR (and remove it from the engine), then add their “Hot” tune.
* Then when you get it running bump the fuel pressure up to about 67-68 psi and you’ll have a very strong runner that will start to find weaknesses elsewhere in your driveline .
Imma cheap-ass sum bit redneck... (actually father of 2 with sports, wife, bills, etc... ) so this is my budge 8.1L swap. I know others say you can get a motor for $1000 but expect to pay 2-3x that to install it... EFFFF DAT!!!!!

************************ Parts Purchased *****************************
2001 8.1L motor/harness/pcm/etc - facebook 8.1L group $1200
Motor Mounts: Energy Suspension 3.1116R - Amazon $55
ORD Big Block Engine Cross Member - ORD $223.50
2002 Silverado diesel gas pedal - car-parts.com $60
6AN Billet Fuel Filter - amazon - $10
AN6 stainless braided fuel line - ebay - $50
454 stock exhaust manifolds - friend - $45
EP381 fuel pump - amazon - $30
12563485 flywheel bolts - amazon - $10
2557583 pilot bearing - amazon - $20
Exhaust gaskets - fel-pro MS95840 - $13

Crank Sensor - duralast - SU1394 - $56
Rear main - Fel-Pro - 8540673 - $24
Wires - Duralast lifetime - 4711 - $32
12559976 EGR Cover - thatgmpartsguy.com - $7 - $4 ship
12580673 EGR Cover gasket - thatgmpartsguy.com - $5


______________________________________________________________
Total....................................
$1844

************************ Parts Expected to Purchase *****************************
harness rework and "Hot Tune" - facebook guy - $300
true dual exhaust with stacks/flaps between rollbar - local - $300

Russell #644123 and #644113 to adapt 6an lines the the stock 8.1L rail
______________________________________________________________
Total....................................
$2444


************************ Parts Purchased *****************************
2002 8.1L motor/harness/pcm/TAC/etc - facebook 8.1L group $700
Motor Mounts: Energy Suspension 3.1116R - Amazon $55
ORD Big Block Engine Cross Member - ORD $223.50
2002 Silverado diesel gas pedal - car-parts.com $60
6AN Billet Fuel Filter - amazon - $10
AN6 stainless braided fuel line - ebay - $50
454 stock exhaust manifolds - friend - $45
EP381 fuel pump - amazon - $30
2557583 pilot bearing - amazon - $20
Exhaust gaskets - fel-pro MS95840 - $13
Wires - Duralast lifetime - 4711 - $32
12559976 EGR Cover - thatgmpartsguy.com - $7 - $4 ship
12580673 EGR Cover gasket - thatgmpartsguy.com - $5

added - MOCA 4PK1010 EPDM Serpentine Belt - amazon - $6
added - 145a alternator - amazon - $78
added - Rear main - Evergreeen RMS10481 - amazon - $20
3705-05293265 - flywheel - partsgeek.com - $125

12563485 flywheel bolts - amazon - $60
______________________________________________________________
Total.................................... $1543

************************ Parts Expected to Purchase *****************************
harness rework and "Hot Tune" - facebook guy - $450
true dual exhaust with stacks/flaps between rollbar - local - $300
Russell #644123 and #644113 to adapt 6an lines the the stock 8.1L rail
______________________________________________________________
Total.................................... $2098


Bringing this back from pg13 as numbers have changed and I have new stuff ordered...

 
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aight.. new parts always look nice.

20201017_155154.jpg

so I have one bolt that i bought a long time ago... so i can put my flywheel on. lol
20201017_155206.jpg




so question. this is the newer crankshaft sensor right? looks it...
20201017_155233.jpg
 
aight.. new parts always look nice.

View attachment 357513

so I have one bolt that i bought a long time ago... so i can put my flywheel on. lol
View attachment 357514




so question. this is the newer crankshaft sensor right? looks it...
View attachment 357515
Damn, that thing is crusty!

I'd get a new crank sensor even if you think that one looks newer than the engine. You ain't getting that sucker out in the truck very easy. If you pull it and it has 3 o-rings on it, that would indicate it's a early sensor that you want to replace anyway. Those are known to stick and or break. Better to do now than later.
 
Damn, that thing is crusty!

I'd get a new crank sensor even if you think that one looks newer than the engine. You ain't getting that sucker out in the truck very easy. If you pull it and it has 3 o-rings on it, that would indicate it's a early sensor that you want to replace anyway. Those are known to stick and or break. Better to do now than later.

it came eight out..
1 o ring. its goin back in. lol20201017_190234.jpg
 
silly updates continue...

rear main tool is $300...
found one on ebay for $35...

flathead screwdriver, mallet and money saved...

20201019_220034.jpg



i forgot they were a 2 piece... you put one on then other..

20201019_220034.jpg

20201019_204959.jpg
 
tried droppin engine in. no go.
ORD BBC engine cross member made engine slide in and couldnt align sm465 shaft...

gonna haveta pull dshaft... trans and xfer... get engine in then fight rest in... frustrated!!!!!
 
also ac tensioner hit front cromm member. wont once engine is pushed back but dont think ac will clear. i dont have ac so gotta remove it anyway....
 
also ac tensioner hit front cromm member. wont once engine is pushed back but dont think ac will clear. i dont have ac so gotta remove it anyway....
Yeah, if the a/c compressor is mounted low, it's not going to fit. It's why most that want to keep a/c without chopping the frame for clearance you'll need the Workhorse/medium duty accessory brackets.
 
wow is she big!!!!!

got it in. notbolted down yet. had to pull trans and transfercase...

fan hits crossmember so had to bend blades. original owner i got engine from belt them so woulda needed a new one. elec fans i guess are required now...

20201110_101059.jpg
 
crappinup the L18 thread... my bad..

bolt on back for engine chain was too long and hit cab. was keeping engine up. sawzall ald when it cut.. entire engine dropped more than a half inch...
was either cut and remove with pliers or yank engine...
 
well engine in... trans and xfer too... she be lookin aight. clip sittin there too. 5 blade dont fit in shroud. well we didnt realize but it fit. scrapin on way in. hah..20201121_114112.jpg 20201121_114120.jpg
 

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